CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Cash flows from operating activities:
Net income	$ 1,024,992	$ 642,407
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	110,960	75,845
Non-cash compensation expense	380,144	405,320
Other non-cash charges and expenses, net	44,016	13,586
Deferred taxes	(108,242)	(190,327)
Changes in assets and liabilites
Increase in Sanofi, Bayer, and trade accounts receivable	(359,829)	(176,079)
Increase in Inventories	(235,645)	(99,706)
(Increase) decrease in prepaid expenses and other assets	(28,209)	34,857
(Decrease) increase in deferred revenue	(59,116)	282,176
(Decrease) increase in accounts payable, accrued expenses and other liabilities	(28,908)	107,438
Total adjustments	(284,829)	453,110
Net cash provided by operating activities	740,163	1,095,517
Cash flows from investing activities:
Purchases of marketable securities	(883,748)	(606,153)
Sales or maturities of marketable securities	379,275	192,091
Capital expenditures	(164,963)	(361,486)
Net cash used in investing activities	(669,436)	(775,548)
Cash flows from financing activities:
Proceeds in connection with capital and facility lease obligations	57,000	5,085
Payments in connection with capital and facility lease obligations	(19,925)	(1,853)
Repayments of convertible senior notes	0	(12,650)
Payments in connection with deduction of outstanding warrants	0	(242,117)
Proceeds from issuance of Common Stock	226,892	89,777
Payments in connection with Common Stock tendered for employee tax obligations	(77,832)	(46,954)
Net cash provided by (used in) financing activities	186,135	(208,712)
Net increase in cash and cash equivalents	256,862	111,257
Cash and cash equivalents at beginning of period	535,203	809,102
Cash and cash equivalents at end of period	$ 792,065	$ 920,359